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RE: stronger exhaust manifold studs?
I have had very good luck using a reverse drill bit. I carefully center
punch the stud remaining in the head. I also have a guide a fabricated that
in most case hold an 1/8" drill bit centered on e stud to start a hole in
the stud. I usually drill completely through the stud with the 1/8" drill
bit and squirt some penetrate oil into it. Then using a reversible angle
head drill and reverse cut drill bit I proceed to drill out the stud. The
drill bit size is slightly under the size of the inner thread diameter of
the stud, this means if I have centered properly on the stud and drilled my
pilot hole true to the axis of the stud I can drill through the stud with
out drilling the head. About 80% of the time I use this method I get about
an 1/8" to 3/16' into the stud with the reverse bit and the bit catches the
stud and screws it out of the head, leaving the threads in the head
completely intact. The reason this works is that the stud was broken by the
manifold pulling on it and not because it was seized in the head and snapped
while trying to turn it out or loosen a rusted nut. If it is seized in the
head this does not work so well. But I almost always use the reverse drill
bits to drill studs just in case.
From: email@example.com [mailto:firstname.lastname@example.org]
Sent: Monday, September 20, 1999 4:04 AM
To: email@example.com; firstname.lastname@example.org
Subject: Re: stronger exhaust manifold studs?
Any idea on how to remove a OM-stud broken 2mm below head
surface, - and
what to replace with ?
The OM is cracked, and i'll be ordering a new two-piece
- Will i have to drill the holes larger ?
- Will that impact durability ?
'87 200(t)Qavant (On Jack Stands)
----- Original Message -----
From: Phil Payne <email@example.com>
Sent: 18. september 1999 17:47
Subject: RE: stronger exhaust manifold studs?
> In message <01BF0171.21AD4900.firstname.lastname@example.org> Don Muirhead
> > I found a couple studs broken on my coupe last weekend
and picked-up a
> > handful from the Dealer today. The ones I grabbed today
are the same as
> > the ones that were replaced under warranty 13 years ago
and at only a
> > ea. (CDN). So I'm not going to worry about the studs
breaking for at
> > 10 years. But that's only my opinion and my $0.75
> Broken studs are a real problem on the turbo cars, perhaps
> weight of the damn thing is entirely carried by the
> I've made two major advances in the last year. One was
> FACOM 287B.8 stud remover. This device slides down over
the stud and
> grips it using three internal rollers - the force applied
to the stud
> during removal is coaxial with the stud and thus old studs
> tempted to snap off. It also helps if you apply
lubrication as soon as
> you have movement and screw the stud back in and out to
spread the oil
> down the threads. Note my criticism of the Dialynx
manifold in this
> regard - in contrast with the Audi original, it's
impossible to get a
> socket onto four of the nuts from above with the Dialynx
> left with a 12mm or 13mm 6-point box (ring) wrench
(spanner) from the
> side, with an awful lot of shear component.
> The second major advance was a FACOM 885 stud remover kit.
> 25-part kit comprising drills, locating sleeves, removing
> driving nuts for the splines. It really is _magic_ in
> So far, on 100,000+ mile ur-quattros, I've taken off about
> In every instance, at least one stud broke - but I've got
it down from
> an average of four to only one on each of the last two.
Both #5 upper,
> as it happens.
> But as before - I'd rather have a stud snap than drag out
> from the head.
> Phil Payne
> UK Audi quattro Owners Club
> Phone: 0385 302803 Fax: 0870 0883933